It is certainly of the best sci-fi tabletop RPGs you can play. The link provided here is the free version of Star Without Number. However, there is an expanded core version that is not free and a new second edition that will be released soon.

Traveller

Traveller is the granddaddy of science fiction role-playing games. There are many editions and tons of supplements that allow almost any kind of sci-fi campaign you can dream up.

Traveller became infamous due to the fact that characters could die during creation. Later editions removed this, but I’ve always wanted to try it.

Even More Sci-Fi Tabletop RPGs

To The Stars

If you find the planet earth restrictive, then leave it or alter it. Take any one of these sci-fi tabletop RPGs and explore what it means to be human, hack the matrix, rob an ancient tomb, or simply enjoy the freedom of the ‘verse.